Web thread changing device for web-loom



Oct. 4, 1966 w. LIEBCHEN 3,276,432

WEB THREAD CHANGING DEVICE FOR WEBLOOM Filed April 9, 1964. 5 Sheets-Sheet 1.

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WEB THREAD CHANGING DEVICE FOR WEB-LOOM Filed April 9, 1964 5 Sheets-Sheet :5

Oct. 4, 1966 w. LIEBCHEN 3,276,482

WEB THREAD CHANGING DEVICE FOR WEB-LOOM Filed April 9, 1964 5 Sheets-Sheet 4 .70 yen/0r: W e/21M Lia/Jaw Oct. 4, 1966 w. LIEBCIHEN 3,275,482

WEB THREAD CHANGING DEVICE FOR WEB-LOOM Filed April 9, 1964 5 Sheets-Sheet 6 I00 I02 100 I04 AM/MK A/ZMQ/ .70 yen/0r United States Patent 3,276,482 WEB THREAD CHANGENG DEVICE FOR WEB-LGQM Waldemar Liebchen, Aschaffenburg, Germany, assignor to Jean Giisken Maschinenfabrik Eisengiesserei, Dullren, Germany Filed Apr. 9, 1964, Ser. No. 358,488

Claims priority, application Germany, Apr. 10, 1963,

G 37,488 12 Claims. (Cl. l39122) The invention relates to an arrangement for supplying and Changing weft threads in gripper web-looms, in which the weft threads extending from the stationary spools to the point where the weft is laid in run over independently movable thread guides, by means of which the particular Weft thread to be laid into the shed of the web is controlled by a pattern arrangement, and a thread presser movable perpendicularly to the thread guides is provided which brings the thread into the path of the feeding gripper. The introduction of the weft thread into the web shed is produced in known types of gripper web-looms by inserting the weft thread extending from an already laid weft by means of the feed gripper up to the center of the shed in the form of a loop (while simultaneously drawing it off the stationary spool), where the loop is gripped by the receiving gripper and the loop part is simultaneously separated from the laid-in weft by a weft thread cutter and is then drawn completely through the shed.

In order to prevent the weft thread after the travel of the receiving gripper from being further drawn off from the stationary spool, it is known, in single gripper web-looms without changeable weft threads, to provide a thread clamp which is operable from the cam shaft of the machine, which releases the weft thread only during the first half of the inward laying movement and then clamps it up to the beginning of the next inward movement.

The application of this expedient to a gripper web-loom with several weft threads which are laid selectively in the shed presents the difficulty that a common weft thread clamps does not hold all the weft threads securely and that during the withdrawal of the cut-off weft thread through the shed further lengths of weft thread will be drawn off by the receiving gripper from the stationary spool.

The basic purpose of the invention is to avoid this difficulty, and to provide a weft thread laying and changing arrangement which, while simple in construction, makes possible a secure control of the change of the weft thread.

According to the invention this purpose is accomplished by laying each weft thread to its engagement in the thread guide over its own thread clamp, and by providing means by which the thread clamp of the particular thread being drawn off during the laying by the feeding gripper is operated, along with the thread guide, to open position by the pattern arrangement.

In a preferred arrangement according to the invention, the thread guides are constructed as guide rods arranged to move perpendicular to the direction of the feed of the weft threads and are movable against the action of springs. In the ends of the rods, guiding eyes for the weft threads are arranged, which, upon the operation of the guide rods, move the weft threads across the path of movement of the feeding gripper under the action of the downwardly movable thread guide. It is an advantageous characteristic of the invention in this preferred [form that each thread rod is cordinated with a lever system operating on the corresponding thread clamp through longitudinally movable driving part and that the 3,276,482 Patented Oct. 4, 1966 pattern arrangement is constructed of periodically advancing cards with projecting bodies by which the longitudinally movable driving parts having nose-shaped projections thereon through individual card-controlled levers are movable against the action of springs into the path of movement of a common, periodically oscillated actuating lever. Advantageously in this arrangement the longitudinally movable driving part is mounted with its center of rotation on one arm of a bell-crank lever mounted on a fixed pivot, the other arm of this bellcrank lever operating upon the thread clamp in a direction to open it. From the arm of the bell-crank lever which operates the thread clamp, a one armed lever mounted on a stationary pivot is moved by a link connection, the free end of this lever engaging the rear end of the thread guide rod.

In order to prevent too early a release of the thread guide and to insure a rapid clamping of the thread upon the operation of the feeding gripper, it is advantageous to provide between the bell-crank lever and the thread clamp a lost motion, which limits the operation of the thread guide to the last part of the swinging movement of the operating lever.

According to a special feature of the invention the thread clamp is constructed as a disc brake, in which the weft threads run between disc brakes movably mounted on a through-bolt, which engages the brake discs on one side with a shoulder and presses them together under the operation of a spring against a stationary abutment, the means for opening the thread clamp engaging the other end of the through-bolt. It is also advantageous to provide the through-bolt in the area between the clamping discs with a transverse bore through which the weft threads pass and to hold it against turning about its longitudinal axis.

Further objects and advantages of the invention will appear more fully from the following description, particularly when taken in conjunction with the accompanying drawings which form a part thereof.

In the drawings:

FIG. 1 is a perspective view of a part of a gripper web-loom with an arrangement on the entrance side of the web shed for introducing the weft threads in accordance with the invention, with the gripper completely withdrawn.

FIGS. 2 to 6 show successive stages in the operation of the device to draw a weft thread through the shed.

FIG. 7 is a plan view of the thread guide arrangement, looked at from the direction of the shed.

FIG. 8 is a longitudinal section through a thread clamp; and

FIG. 9 is a plan view of several of the thread clamps.

The feed gripper 10 is shown in FIG. 1 in its fully withdrawn position. A weft thread 12 runs from a stationary spool 14 through a thread brake 16, a thread clamp 18 and a guide eye 20 to a previously laid weft in the woven material 22. A thread presser 24 is carried at the end of a rod 28 which is movably guided in a guide 26 fixed on the machine frame, and is moved up and down by a double-armed lever 30 which in turn is operated by a cam 34 mounted on a shaft 32 driven synchronously with the feed of the web. A second cam 36 mounted on the shaft 32 moves, through a double-armed lever 38 and a rod 40, moves a weft thread cutter 42, which is mounted on a stationarily journaled lever 44, periodically into the neighborhood of the edge of the material, where the arm 44 abuts against a stationary abutment 46 carried by the machine frame and the rod 40, when it is lifted further, operates the cutting knife 48 mounted inside the thread guide cutter against the operation of the compression spring 50.

What has been heretofore described is known in principle in conventional gripper web-looms without weft thread interchange.

In order to be able to introduce into the shed, during the consecutive insertions, dilferentweft threads, especially those with different colors for achieving a color pattern, the guide eyes 20 are positioned on the ends of movable guide rods 52, which are all arranged as shown in FIG. 7 to be movable longitudinally in a bearing block 54 stationary with the machine frame. Through the guide eye 20 of each guide rod 52 there runs, coming from the corresponding stationary spool, one of the different weft threads, to the last weft laid with this thread in the fabric 22. The guide rods 52 are held by tension springs 56 in a position in which the guide eyes 20 hold the weft threads 12 out of the range of movement of the thread presser 24. In order to lay the desired weft thread in the web shed, the corresponding thread guide rod 52 is pushed in the guide block 54 against the operation of the spring 56, in a manner to be explained below, so that the weft thread is engaged by the thread presser 24 in its downward movement and moved to a position where it is engageable by the feed gripper 10 which takes it into the shed.

Such an arrangement is also known.

According to the invention, each weft thread 12 before its insertion in the guide eye is led through a thread clamp 18, and each thread clamp 18 is, by special mechanism, operated together with the corresponding thread guide from a common pattern arrangement. Because the mechanism of each weft thread is the same and likewise the guide rods 52 are arranged generally one above the other, and insofar as the construction and operation are concerned they constitute a single constructive group, the disclosure in FIGS. 1 to 6 is restricted to the showing of the necessary parts for the laying of one weft thread.

The free ends of each thread guide rod 52 extend on the side remote from the weft threads 12 out of bearing block 54 and constitute at their rear ends engaging surfaces facing a single-armed lever 58, which, along with the corresponding single-armed levers of the remainder of the guide rods, are journalled on a common vertical axis 60 mounted in the machine frame. A link 62 connects the one-armed lever 58 operatively with a bell-crank lever 64, which in common with the corresponding bellcrank levers of the whole group are journalled on an axis 66 mounted in the machine frame. The link 62 connects to one arm of the bell crank lever 64, the free end of which in a manner described below, operates the thread clamp 18.

A bar 68 is pivoted on the other arm of bell-crank lever 64, which constitutes a longitudinally movable drive memlber for the leverage unit composed of the bell-crank lever 64, the link 62 and the one-armed lever 58. The bar 68 is provided on one of its longer edges with a noselike projection 70, which forms a part for engagement by a shifting lever or member 72 common to all the bars of the group. The two-armed shifting lever 72 is pivoted on the machine frame. One arm of lever 72 has an edge 74 engageable with any of the bar projections 70. The other arm is connected by a connecting rod 76 to a lever 78 carrying a roller which engages cam disc 80 and is moved, against the action of spring 82 connected to the frame, periodically back and forth synchronously with the stroke of the sley. A tension spring 84 holds the bar 68 normally in a position in which the nose-shaped projection 70 lies outside the path of swinging of the edge 74 of the shifting lever 72.

With each bar 68 is associated a two-armed cardengaging lever 86, all of these being mounted on a common axis 88 carried by the frame. One arm of lever 86 engages bar 68, while the other end carries a feeler 90, which is located close to the uppermost card 92 of a pattern arrangement 94. The cards 92, which are advanced periodically in synchronism with the stroke of the sley,

are provided, in accordance with the desired pattern program, with lifting bodies 96, by engagement of which with the feelers the card-engaging levers are operated.

The thread clamp, as shown in FIGS. 8 and 9, comprises a disc brake clamp. On one end of a throughbolt 98 are arranged two brake discs 100 and 102, between which the weft thread 12 runs from the spool 14 to the guide eye 20. Bolt 98 is longitudinally slidable through bushing 104 mounted in block 106. The end of bolt 98 remote from the brake discs 100, 102 is provided with an annular flange 108, between which and the block 106 is arranged a compression spring 110. Spring 110 urges bolt 98 to the right (FIG. 8), which through a key 112 extending through the other end of the bolt and engaging the outer brake disc 100 presses it against the inner disc 102 which rests against the block 106, so that the thread is clamped between the brake discs. The rear end 114, enlarged by the flange 108, constitutes an engaging surface for one arm of the lever 64, so as to move the bolt 98 to the left (FIG. 8) and open the thread clamp, as will be explained below.

In order to prevent the thread, when the thread clamp is opened, from falling out from between the discs, the bolt 98 is provided with a transverse slot 116 through which the thread is led. To make sure that slot 116 points in the right direction for the thread, flange 100 is provided at one point of its periphery with a segmental recess 118 (FIG. 9). In this engages a guide bolt 120 which extends parallel to bolt 98, which has a cut-away end extending into hole 122 in block 106, where it is held by set-screw 124.

The device operates as follows:

When the pattern device 94 moves a new card to the uppermost position (the feed gripper 10 and the cutter 42 being withdrawn, as shown in FIG. 1), the lifting member 96 engages and lifts the feeler 90 of one of the card-engaging levers 86 (for example, the one shown in FIGS. 1 to 6), and swings the lever around its axis. The other arm of lever 86 then presses against bar 68, swinging it against the resistance of spring 84, so that projection 70 moves into the path of the swinging movement of lever edge 74. As the lever 72 oscillates, the projection 70 is engaged by edge '74 and moved along with it, moving the bar 68 and thereby turning bell-crank lever 64 and, through link 62, one-armed lever 58. Lever 58 pushes the end of guide rod 52 which carries eye 20 out of the block 54, against spring 56, and bring the weft thread 12 into the path of thread presser 24 (FIG. 2). The end of bell-crank lever 64 directed towards thread clamp 18 goes through a lost motion, until, after closing the gap 126 it engages the enlarged rear face 114 of bolt 98. Upon a further swinging of lever 64, bolt 98 is pushed to the left (FIG. 8), against the action of spring 110, so that the pressure on brake discs 100, 102 is removed and the thread 12 is released.

When the guide rod 52 with the eye 20 and the weft thread 12 running through it has reached its outermost position away from block 54 and thread clamp '18 is completely open, the downwardly moving thread presser 24 engages the weft thread 112 with its hook-shaped end and by further downward movement positions it in front of the feeding gripper 10, which carries it in the form of a loop to the center of the web shed. This causes the weft thread to loop around a point 128 of the forked end of the thread presser 24 (FIG. 4). Further movement of the weft thread 12 causes it to slip off the point 128 and to enter the cutting space of the thread cutter 42 (FIG. 5) which, by means of the cutter blade 48, cuts off the thread from the previously laid weft almost simultaneously with its transfer to the cutting device (FIG. 6). The cut-off loop part 134 of the weft thread 12 is then drawn in the usual way completely through the web shed by the hook-shaped receiving member 132 and beaten up to the web.

Because of the opening of the thread clamp 18 at the end of the forward movement of the guiding rod 52, the Weft thread, while it is being carried by feeding gripper into the web shed 136 in the form of a loop, is drawn off as needed from the spool 14, so that the separate thread brake 16 provided for each Weft thread makes it possible to maintain a desirable low thread tension.

The cam disc 80 is so constructed and arranged that the common lever 72 begins its return movement shortly before the transfer of the weft thread from the feed gripper 10 to the receiving member 132, or shortly before the cutting action of the shear 42. The thread clamp 18 is thus closed simultaneously with the transfer of the weft thread to the cutter 42 and any further withdrawal of the weft thread from the spool 14 is prevented.

While I have described herein one embodiment of my invention, I wish it to be understood that I do not intend to limit myself thereby except Within the scope of the claims hereto or hereinafter appended.

I claim:

1. A device for inserting and changing weft threads in the shed of a Web loom, comprising a plurality of holders for supplies of weft threads, a plurality of thread guides, means mounting the thread guides for movement independently of each other between first and second positions, means normally holding the thread guides in the first position, a thread presser movable transversely with respect to the path of the weft threads, each of said thread guides in its second position holding a weft thread in the path of movement of said thread presser, a feeder mounted for movement into and out of the shed, movement of the thread presser carrying a weft thread engaged thereby into the path of the feeder to be carried into the shed, independently releasable, normally operative thread clamps in the paths of the weft threads between the holders and the guides, means for selectively moving any one of the thread guides to the second position comprising a shifting member, means for periodically moving said shifting member in synchronism with the movements of the feeder, independent means operatively connected to each thread guide and clamp for moving the thread guide to the second position and releasing the clamp, and pattern means operatively connected to each such independent means for selectively oper-ably connecting one of such independent means to the shifting member for operation thereby to move the thread guide to the second position and release the corresponding clamp.

2. In a device as claimed in claim 1, in which the thread guides comprise rods mounted for longitudinal movement in a direction transverse to the path of the weft thread with eyes thereon for receiving the weft threads, and the independent means for moving the guides and releasing the clamps comprises for each weft thread a lever system operatively engageable with the thread guide and clamp and a longitudinally slidable member operatively connected to said lever system, said pattern means selectively shifting one of said members.

3. In a device as claimed in claim 1, the shifting member comprising a lever oscillated in synchronism with the operation of said feeder, said independent means comprising a longitudinally movable member for each weft thread and a lever system for each weft thread operatively engageable with the corresponding thread guide and clamp, said longitudinally movable members each being swingable between a normal position and a second position, said lever having a part which swings in a path adjacent the second positions of said members, said lever and members having cooperating means engageable in the second positions of the members to move them longitudinally, said pattern means selectively moving said members to said second position.

4. In a device as claimed in claim 1, the independent means for moving the guides and releasing the clamps comprising a lever having one end adjacent to and engageable with the thread clamp to open the clamp, an elongated member pivoted on said lever, pattern means operatively engageable with said member to move it in a direction to swing said lever, and means connected to said lever and operatively engageable with the thread guide.

5. A device as claimed in claim 4 in which said last means comprises a second lever and a link connecting said levers.

6. In a device as claimed in claim 4, said lever having the part engageable with the thread guide normally spaced from the clamp to provide a lost motion therebetween.

7. In a device as claimed in claim 4, each thread clamp comprising a bolt, a pair of adjacent discs slidably mounted on the bolt, a frame, said bolt being slidably mounted in the frame with one disc engaged against the frame, means carried by the bolt engaging the other disc, and means resiliently urging the bolt in a direction to clamp the discs against the frame.

8. In a device as claimed in claim 7, said lever engaging the end of the bolt remote from the discs.

9. In a device as claimed in claim 8, the bolt having a transverse opening therethrough in the area of the discs, and means carried by the frame and engaging the bolt to prevent rotation thereof.

10. In a device as claimed in claim 9, said lever having the part engageable with the thread guide normally spaced from the clamp to provide a lost motion t-herebetween.

11. In a device as claimed in claim 1, each thread clamp comprising a bolt, a pair of adjacent discs slidably mounted on the bolt, a frame, said bolt being slidably mounted in the frame with one disc engaged against the frame, means carried by the bolt engaging the other disc, and means resiliently urging the bolt in a direction to clamp the discs against the frame.

12. In a device as claimed in claim 11, the bolt having a transverse opening therethrough in the area of the discs, and means carried by the frame and engaging the bolt to prevent rotation thereof.

References (Iited by the Examiner UNITED STATES PATENTS 1,943,012 1/1934 Gabler 139-122 2,407,773 9/ 1946 Fletcher 139-12'3 2,429,394 10 1947 Clai-rmont 139--123 2,462,812 2/1949 Parry et al. 242- 2,629,561 2/1953 Heizer 242-150 X 2,814,315 11/1957 Lyle et al 13912 3 2,837,124 6/ 1958 Ancet et al 1 39-123 2,912,185 11/1959 Vossen 24215O 3,092,150 6/ 1963 Birmans et al 139-122 3,158,182 11/1964 Dewas 139122 X 3,181,569 5/1965 Carroll 1 39-122 FOREIGN PATENTS 1,132,916 11/1956 France. 1,302,217 7/ 1962 France. 1,309,084 10/ 1962 France.

396,961 8/1933 Great Britain.

443,251 2/ 1936 Great Britain.

MERV IN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

I. KEE CHI, Assistant Examiner. 

1. A DEVICE FOR INSERTING AND CHANGING WEFT THREADS IN THE SHED OF A WEB LOOM, COMPRISING A PLURALITY OF HOLDERS FOR SUPPLIES OF WEFT THREADS A PLURALITY OF THREADS GUIDES, MEANS MOUNTING THE THREAD GUIDES FOR MOVEMENT INDEPENDENTLY OF EACH OTHER BETWEEN FIRST AND SECOND POSITIONS, MEANS NORMALLY HOLDING THE THREAD GUIDES IN THE FIRST POSITION, A THREAD PRESSER MOVABLE TRANSVERSELY WITH RESPECT TO THE PATH OF THE WEFT THREADS, EACH OF SAID THREAD GUIDES IN ITS SECOND POSITION HOLDING A WEFT THREAD IN THE PATH OF MOVEMENT OF SAID THREAD PRESSER, A FEEDER MOUNTED FOR MOVEMENT INTO AND OUT OF THE SHED, MOVEMENT OF THE THREAD PRESSER CARRYING A WEFT THREAD ENGAGED THEREBY INTO THE PATH OF THE FEEDER TO BE CARRIED INTO THE SHED, INDEPENDENTLY RELEASABLE, NORMALLY OPERATIVE THREAD CLAMPS IN THE PATHS OF THE WEFT THREADS BETWEEN THE HOLDERS AND THE GUIDES, MEANS FOR SELECTIVELY MOVING ANY ONE OF THE THREAD GUIDES TO THE SECOND POSITION COMPRISING A SHIFTING MEMBER, MEANS FOR PERIODICALLY MOVING SAID SHIFTING MEMBER IN SYNCHRONISM WITH THE MOVEMENTS OF THE FEEDER, INDEPENDENT MEANS OPERATIVELY CONNECTED TO EACH THREAD GUIDE AND CLAMP FOR MOVING THE THREAD GUIDE TO THE SECOND POSITION AND RELEASING THE CLAMP, AND PATTERN MEANS OPERATIVELY CONNECTED TO EACH SUCH INDEPENDENT MEANS FOR SELECTIVELY OPERABLY CONNECTING ONE OF SUCH INDEPENDENT MEANS TO THE SHIFTING MEMBER FOR OPERATION THEREBY TO MOVE THE THREAD GUIDE TO THE SECOND POSITION AND RELEASE THE CORRESPONDING CLAMP. 